1. Technical Field
The disclosure relates to LED (light emitting diode) lamps, and more particularly to an improved LED lamp having good heat dissipation performance.
2. Description of Related Art
A typical LED lamp includes a circuit board and a plurality of LEDs mounted on the circuit board. The circuit board includes a heat conductive layer, a heat conductive but electrically insulating layer, a bonding layer and a circuit layer, which are upwardly and successively layer-by-layer stacked. The circuit layer includes a plurality of mounting areas corresponding to the LEDs, respectively. Each mounting area includes a first electrode, a second electrode and a heat conductive section spaced from the first electrode and the second electrode. The LED is mounted on the heat conductive section of the circuit layer and electrically connected with the first electrode and the second electrode. The heat generated by the LED is transferred through the circuit layer, the bonding layer, the insulating layer and then to the heat conductive layer.
A width of the heat conductive section is a key factor influencing the heat conductive performance of the LED lamp. If the heat conductive section has a greater width, the heat conductive section will have a greater contact area with the LED thereby improving the heat conductive performance of the LED lamp. A spacing between the heat conductive section and each of the first and second electrodes of the mounting area influences the electrical performance of the LED lamp. If the spacing between the heat conductive section and each of the first and second electrodes of the mounting area is greater, a current leakage becomes smaller thereby improving the electrical performance of the LED lamp.
However, with the LED lamp becoming compact, the width of the heat conductive section and the spacing between each of the electrodes and the heat conductive section of the mounting area are mutually constrained. In other words, when the heat conductive section is provided with a greater width to improve the heat dissipating performance without increasing the mounting area of the LED lamp, the spacing between each of the electrodes and the heat conductive section will be decreased thereby influencing the electrical performance of the LED lamp. Contrarily, when the spacing between each of the electrodes and the heat conductive section of the mounting area is provided with a greater width to reduce the current leakage without increasing the mounting area of the LED lamp, the width of the heat conductive section will be decreased thereby influencing the heat conductive performance of the LED lamp, and the heat of the LED lamp cannot be adequately and timely removed.
For the foregoing reasons, therefore, there is a need in the art for an LED lamp which can overcome the limitations.